package com.ff.common.dao.mybatis;

import java.io.InputStream;
import java.io.Reader;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.ibatis.builder.BaseBuilder;
import org.apache.ibatis.builder.BuilderException;
import org.apache.ibatis.builder.xml.XMLMapperBuilder;
import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.datasource.DataSourceFactory;
import org.apache.ibatis.executor.ErrorContext;
import org.apache.ibatis.executor.loader.ProxyFactory;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.mapping.DatabaseIdProvider;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.plugin.Interceptor;
import org.apache.ibatis.reflection.MetaClass;
import org.apache.ibatis.reflection.factory.ObjectFactory;
import org.apache.ibatis.reflection.wrapper.ObjectWrapperFactory;
import org.apache.ibatis.session.AutoMappingBehavior;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.LocalCacheScope;
import org.apache.ibatis.transaction.TransactionFactory;
import org.apache.ibatis.type.JdbcType;

public class FFXmlConfigBuilder extends BaseBuilder
{
	private boolean parsed;
	private XPathParser parser;
	private String environment;

	public FFXmlConfigBuilder(Reader reader) {
	    this(reader, null, null);
	  }

	public FFXmlConfigBuilder(Reader reader, String environment) {
	    this(reader, environment, null);
	  }

	public FFXmlConfigBuilder(Reader reader, String environment, Properties props) {
	    this(new XPathParser(reader, true, props, new XMLMapperEntityResolver()), environment, props);
	  }

	public FFXmlConfigBuilder(InputStream inputStream) {
	    this(inputStream, null, null);
	  }

	public FFXmlConfigBuilder(InputStream inputStream, String environment) {
	    this(inputStream, environment, null);
	  }

	public FFXmlConfigBuilder(InputStream inputStream, String environment, Properties props) {
	    this(new XPathParser(inputStream, true, props, new XMLMapperEntityResolver()), environment, props);
	  }

	private FFXmlConfigBuilder(XPathParser parser, String environment, Properties props) {
	    super(new FFConfiguration());
	    ErrorContext.instance().resource("SQL Mapper Configuration");
	    this.configuration.setVariables(props);
	    this.parsed = false;
	    this.environment = environment;
	    this.parser = parser;
	  }

	public Configuration parse()
	{
		if (parsed)
		{
			throw new BuilderException("Each XMLConfigBuilder can only be used once.");
		}
		parsed = true;
		parseConfiguration(parser.evalNode("/configuration"));
		return configuration;
	}

	private void parseConfiguration(XNode root)
	{
		try
		{
			propertiesElement(root.evalNode("properties")); // issue #117 read
															// properties first
			typeAliasesElement(root.evalNode("typeAliases"));
			pluginElement(root.evalNode("plugins"));
			objectFactoryElement(root.evalNode("objectFactory"));
			objectWrapperFactoryElement(root.evalNode("objectWrapperFactory"));
			settingsElement(root.evalNode("settings"));
			environmentsElement(root.evalNode("environments")); // read it after
																// objectFactory
																// and
																// objectWrapperFactory
																// issue #631
			databaseIdProviderElement(root.evalNode("databaseIdProvider"));
			typeHandlerElement(root.evalNode("typeHandlers"));
			mapperElement(root.evalNode("mappers"));
		} catch (Exception e)
		{
			throw new BuilderException("Error parsing SQL Mapper Configuration. Cause: " + e, e);
		}
	}

	private void typeAliasesElement(XNode parent)
	{
		if (parent != null)
		{
			for (XNode child : parent.getChildren())
			{
				if ("package".equals(child.getName()))
				{
					String typeAliasPackage = child.getStringAttribute("name");
					configuration.getTypeAliasRegistry().registerAliases(typeAliasPackage);
				} else
				{
					String alias = child.getStringAttribute("alias");
					String type = child.getStringAttribute("type");
					try
					{
						Class<?> clazz = Resources.classForName(type);
						if (alias == null)
						{
							typeAliasRegistry.registerAlias(clazz);
						} else
						{
							typeAliasRegistry.registerAlias(alias, clazz);
						}
					} catch (ClassNotFoundException e)
					{
						throw new BuilderException("Error registering typeAlias for '" + alias + "'. Cause: " + e, e);
					}
				}
			}
		}
	}

	private void pluginElement(XNode parent) throws Exception
	{
		if (parent != null)
		{
			for (XNode child : parent.getChildren())
			{
				String interceptor = child.getStringAttribute("interceptor");
				Properties properties = child.getChildrenAsProperties();
				Interceptor interceptorInstance = (Interceptor) resolveClass(interceptor).newInstance();
				interceptorInstance.setProperties(properties);
				configuration.addInterceptor(interceptorInstance);
			}
		}
	}

	private void objectFactoryElement(XNode context) throws Exception
	{
		if (context != null)
		{
			String type = context.getStringAttribute("type");
			Properties properties = context.getChildrenAsProperties();
			ObjectFactory factory = (ObjectFactory) resolveClass(type).newInstance();
			factory.setProperties(properties);
			configuration.setObjectFactory(factory);
		}
	}

	private void objectWrapperFactoryElement(XNode context) throws Exception
	{
		if (context != null)
		{
			String type = context.getStringAttribute("type");
			ObjectWrapperFactory factory = (ObjectWrapperFactory) resolveClass(type).newInstance();
			configuration.setObjectWrapperFactory(factory);
		}
	}

	private void propertiesElement(XNode context) throws Exception
	{
		if (context != null)
		{
			Properties defaults = context.getChildrenAsProperties();
			String resource = context.getStringAttribute("resource");
			String url = context.getStringAttribute("url");
			if (resource != null && url != null)
			{
				throw new BuilderException(
						"The properties element cannot specify both a URL and a resource based property file reference.  Please specify one or the other.");
			}
			if (resource != null)
			{
				defaults.putAll(Resources.getResourceAsProperties(resource));
			} else if (url != null)
			{
				defaults.putAll(Resources.getUrlAsProperties(url));
			}
			Properties vars = configuration.getVariables();
			if (vars != null)
			{
				defaults.putAll(vars);
			}
			parser.setVariables(defaults);
			configuration.setVariables(defaults);
		}
	}

	private void settingsElement(XNode context) throws Exception
	{
		if (context != null)
		{
			Properties props = context.getChildrenAsProperties();
			// Check that all settings are known to the configuration class
			MetaClass metaConfig = MetaClass.forClass(Configuration.class);
			for (Object key : props.keySet())
			{
				if (!metaConfig.hasSetter(String.valueOf(key)))
				{
					throw new BuilderException("The setting " + key
							+ " is not known.  Make sure you spelled it correctly (case sensitive).");
				}
			}
			configuration.setAutoMappingBehavior(
					AutoMappingBehavior.valueOf(props.getProperty("autoMappingBehavior", "PARTIAL")));
			configuration.setCacheEnabled(booleanValueOf(props.getProperty("cacheEnabled"), true));
			configuration.setProxyFactory((ProxyFactory) createInstance(props.getProperty("proxyFactory")));
			configuration.setLazyLoadingEnabled(booleanValueOf(props.getProperty("lazyLoadingEnabled"), false));
			configuration.setAggressiveLazyLoading(booleanValueOf(props.getProperty("aggressiveLazyLoading"), true));
			configuration
					.setMultipleResultSetsEnabled(booleanValueOf(props.getProperty("multipleResultSetsEnabled"), true));
			configuration.setUseColumnLabel(booleanValueOf(props.getProperty("useColumnLabel"), true));
			configuration.setUseGeneratedKeys(booleanValueOf(props.getProperty("useGeneratedKeys"), false));
			configuration
					.setDefaultExecutorType(ExecutorType.valueOf(props.getProperty("defaultExecutorType", "SIMPLE")));
			configuration
					.setDefaultStatementTimeout(integerValueOf(props.getProperty("defaultStatementTimeout"), null));
			configuration
					.setMapUnderscoreToCamelCase(booleanValueOf(props.getProperty("mapUnderscoreToCamelCase"), false));
			configuration.setSafeRowBoundsEnabled(booleanValueOf(props.getProperty("safeRowBoundsEnabled"), false));
			configuration.setLocalCacheScope(LocalCacheScope.valueOf(props.getProperty("localCacheScope", "SESSION")));
			configuration.setJdbcTypeForNull(JdbcType.valueOf(props.getProperty("jdbcTypeForNull", "OTHER")));
			configuration.setLazyLoadTriggerMethods(
					stringSetValueOf(props.getProperty("lazyLoadTriggerMethods"), "equals,clone,hashCode,toString"));
			configuration
					.setSafeResultHandlerEnabled(booleanValueOf(props.getProperty("safeResultHandlerEnabled"), true));
			configuration.setDefaultScriptingLanguage(resolveClass(props.getProperty("defaultScriptingLanguage")));
			configuration.setCallSettersOnNulls(booleanValueOf(props.getProperty("callSettersOnNulls"), false));
			configuration.setLogPrefix(props.getProperty("logPrefix"));
			configuration.setLogImpl(resolveClass(props.getProperty("logImpl")));
			configuration.setConfigurationFactory(resolveClass(props.getProperty("configurationFactory")));
		}
	}

	private void environmentsElement(XNode context) throws Exception
	{
		if (context != null)
		{
			if (environment == null)
			{
				environment = context.getStringAttribute("default");
			}
			for (XNode child : context.getChildren())
			{
				String id = child.getStringAttribute("id");
				if (isSpecifiedEnvironment(id))
				{
					TransactionFactory txFactory = transactionManagerElement(child.evalNode("transactionManager"));
					DataSourceFactory dsFactory = dataSourceElement(child.evalNode("dataSource"));
					DataSource dataSource = dsFactory.getDataSource();
					Environment.Builder environmentBuilder = new Environment.Builder(id).transactionFactory(txFactory)
							.dataSource(dataSource);
					configuration.setEnvironment(environmentBuilder.build());
				}
			}
		}
	}

	private void databaseIdProviderElement(XNode context) throws Exception
	{
		DatabaseIdProvider databaseIdProvider = null;
		if (context != null)
		{
			String type = context.getStringAttribute("type");
			if ("VENDOR".equals(type))
				type = "DB_VENDOR"; // awful patch to keep backward
									// compatibility
			Properties properties = context.getChildrenAsProperties();
			databaseIdProvider = (DatabaseIdProvider) resolveClass(type).newInstance();
			databaseIdProvider.setProperties(properties);
		}
		Environment environment = configuration.getEnvironment();
		if (environment != null && databaseIdProvider != null)
		{
			String databaseId = databaseIdProvider.getDatabaseId(environment.getDataSource());
			configuration.setDatabaseId(databaseId);
		}
	}

	private TransactionFactory transactionManagerElement(XNode context) throws Exception
	{
		if (context != null)
		{
			String type = context.getStringAttribute("type");
			Properties props = context.getChildrenAsProperties();
			TransactionFactory factory = (TransactionFactory) resolveClass(type).newInstance();
			factory.setProperties(props);
			return factory;
		}
		throw new BuilderException("Environment declaration requires a TransactionFactory.");
	}

	private DataSourceFactory dataSourceElement(XNode context) throws Exception
	{
		if (context != null)
		{
			String type = context.getStringAttribute("type");
			Properties props = context.getChildrenAsProperties();
			DataSourceFactory factory = (DataSourceFactory) resolveClass(type).newInstance();
			factory.setProperties(props);
			return factory;
		}
		throw new BuilderException("Environment declaration requires a DataSourceFactory.");
	}

	private void typeHandlerElement(XNode parent) throws Exception
	{
		if (parent != null)
		{
			for (XNode child : parent.getChildren())
			{
				if ("package".equals(child.getName()))
				{
					String typeHandlerPackage = child.getStringAttribute("name");
					typeHandlerRegistry.register(typeHandlerPackage);
				} else
				{
					String javaTypeName = child.getStringAttribute("javaType");
					String jdbcTypeName = child.getStringAttribute("jdbcType");
					String handlerTypeName = child.getStringAttribute("handler");
					Class<?> javaTypeClass = resolveClass(javaTypeName);
					JdbcType jdbcType = resolveJdbcType(jdbcTypeName);
					Class<?> typeHandlerClass = resolveClass(handlerTypeName);
					if (javaTypeClass != null)
					{
						if (jdbcType == null)
						{
							typeHandlerRegistry.register(javaTypeClass, typeHandlerClass);
						} else
						{
							typeHandlerRegistry.register(javaTypeClass, jdbcType, typeHandlerClass);
						}
					} else
					{
						typeHandlerRegistry.register(typeHandlerClass);
					}
				}
			}
		}
	}

	private void mapperElement(XNode parent) throws Exception
	{
		if (parent != null)
		{
			for (XNode child : parent.getChildren())
			{
				if ("package".equals(child.getName()))
				{
					String mapperPackage = child.getStringAttribute("name");
					configuration.addMappers(mapperPackage);
				} else
				{
					String resource = child.getStringAttribute("resource");
					String url = child.getStringAttribute("url");
					String mapperClass = child.getStringAttribute("class");
					if (resource != null && url == null && mapperClass == null)
					{
						ErrorContext.instance().resource(resource);
						InputStream inputStream = Resources.getResourceAsStream(resource);
						XMLMapperBuilder mapperParser = new XMLMapperBuilder(inputStream, configuration, resource,
								configuration.getSqlFragments());
						mapperParser.parse();
					} else if (resource == null && url != null && mapperClass == null)
					{
						ErrorContext.instance().resource(url);
						InputStream inputStream = Resources.getUrlAsStream(url);
						XMLMapperBuilder mapperParser = new XMLMapperBuilder(inputStream, configuration, url,
								configuration.getSqlFragments());
						mapperParser.parse();
					} else if (resource == null && url == null && mapperClass != null)
					{
						Class<?> mapperInterface = Resources.classForName(mapperClass);
						configuration.addMapper(mapperInterface);
					} else
					{
						throw new BuilderException(
								"A mapper element may only specify a url, resource or class, but not more than one.");
					}
				}
			}
		}
	}

	private boolean isSpecifiedEnvironment(String id)
	{
		if (environment == null)
		{
			throw new BuilderException("No environment specified.");
		} else if (id == null)
		{
			throw new BuilderException("Environment requires an id attribute.");
		} else if (environment.equals(id))
		{
			return true;
		}
		return false;
	}

}
